anti-smoker; person who dislikes smoking
Often used for someone who actively avoids or opposes smoking, not just a mild preference. The term can carry a slightly militant or activist connotation, but is also used neutrally.
See also: 愛煙家
He is an anti-smoker and hates cigarette smoke.
Recently, the number of anti-smokers has been increasing.
Compound of 嫌 (けん, 'dislike') + 煙 (えん, 'smoke') + 家 (か, 'person'). The exact origin is uncertain, but it follows a common pattern for labeling people by their stance or habit.